A lipid panel, often called a lipid profile, is a standard blood test used to determine your cholesterol levels. The test measures the amount of total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides in your bloodstream.

A lipid profile is the first line of defense against high cholesterol, which puts you at risk of heart attack and stroke. If your lipid profile shows that your cholesterol is too high, you and your doctor can take measures to bring your levels down to a healthy range.

To get the most accurate reading, many doctors ask you to fast before a cholesterol test.

Here are the typical requirements:

The first requirement for a fasting cholesterol test is to stop eating food for 10 to 12 hours beforehand, according to Cleveland Clinic. This includes broths, bouillons, soups, and gelatins that may be allowed before other medical tests.

Consider asking for an early morning appointment so the fasting period can largely take place while you’re asleep.

Eating food within the recommended 10- to 12-hour fasting period may not affect your levels of total cholesterol and HDL cholesterol, according to Henry Ford Health, but it can cause your triglyceride levels to rise temporarily. This is the main reason for the fasting requirement.

The only liquid you may drink during the fasting period is water, says Cleveland Clinic. That means skipping your morning coffee or tea and any other beverages, such as milk, soda, and juice.